1. Field of the Invention
This invention relates to a multimode input circuit formed in a liquid crystal display (LCD) driving integrated circuit, for example, and more particularly to a multimode input circuit for receiving two signals having amplitude variations different from each other, converting the received signal into a preset potential and supplying the converted potential to an internal circuit of the integrated circuit.
2. Description of the Related Art
An LCD data driving integrated circuit (IC) for serially receiving LCD display data inputs, converting them into the parallel form, converting them into LCD driving voltages and then outputting the driving voltages may be sometimes divided into plural sections which are arranged in the horizontal direction of the LCD panel. With the above arrangement, in a case where a plurality of data driving ICs are cascade-connected to serially transfer LCD display data inputs, the signal level of the display data input to the first-stage data driving IC and the signal level of the display data input to one of the succeeding stage data driving ICs are different from each other, and respectively set to 12 V and 5 V, for example. That is, as the input signal to the data driving ICs, a first input signal (for example, 12 V system) having an amplitude varying in a range between a first reference potential and a first power source potential and a second input signal (for example, 5 V system) having an amplitude varying in a range between a second reference potential and a second power source potential may be used.
Therefore, at the time of design, it is necessary to form circuit patterns for the input circuits having different circuit constructions for the signals having two different amplitude variations.